Fixed Assets - Additional Information (Detail) (USD $) In Billions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Depreciation expense relating to fixed assets	$ 2.9	$ 2.7	$ 2.4
Buildings & improvements [Member] | Minimum [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives	30 years
Buildings & improvements [Member] | Maximum [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives	40 years
Machinery & equipment [Member] | Minimum [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives	5 years
Machinery & equipment [Member] | Maximum [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives	10 years
Seismic vessels [Member] | Minimum [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives	20 years
Seismic vessels [Member] | Maximum [Member]
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]
Useful lives	30 years